About implementing rny_string (with.Java)

In this article, we learned about implementing rny_string.

We’ll do this by solving coding test problems, reflecting on the problems we solved, and learning about other ways to solve them.

Let’s start with the problem

Problem

We want to play a trick on a string by taking advantage of the fact that “m” and “rn” look similar.

Given a string rny_string, write a solution function that returns a string with all the “m”s in rny_string replaced with “rn”.

Example input and output

My solution to the problem

class Solution {
    public String solution(String rny_string) {
        StringBuilder answer = new StringBuilder(rny_string);
        for(int i = 0; i < answer.length(); i++){
            if(answer.charAt(i) == 'm'){
                answer.replace(i,i,"rn");
            }
        }
        } return answer.toString();
    }
}

Solution

StringBuilder answer = new StringBuilder(rny_string);: Converts the given string rny_string into a StringBuilder object that can be modified. StringBuilder is a class for efficiently modifying strings.

for(int i = 0; i < answer.length(); i++): Starts a loop that traverses the string character by character. The loop is repeated for the length of the string.

if(answer.charAt(i) == ‘m’): Checks if the character at the current index i is ‘m’.

answer.replace(i, i + 1, “rn”);: Replace ‘m’ with “rn” The replace method replaces the string between starting index i and ending index i + 1 with “rn”.

return answer.toString();: Converts the StringBuilder object back to a string and returns the result.

The code implemented in this way generates and returns a new string by replacing all the “m” characters in the input string with “rn”. We are working efficiently by using StringBuilder for string modification.